Recently, along with initiation of digital broadcasting, data broadcasting in a BML (Broadcast Markup Language) scheme has been widely carried out. In data broadcasting, data is transmitted in a data carousel transmission scheme of transmitting data in information transmission units referred to as modules. In the data carousel transmission scheme, transmission can be repeatedly carried out in the units referred to as a data carousel which is gathering of some modules, and a receiver can display data broadcasting such as news and weather forecasts at any time.
The present applicant has proposed a technique of superimposing and displaying the images of a sign language on the images of content by multiplexing and transmitting the modules of the data carousel storing sign-language word images (for example, see Patent Literature 1).